Gas cell display panel utilizing corrugated electrodes

ABSTRACT

A display panel utilizing an array of gas-filled cells in an insulator sheet the cells being arranged in upper and lower layers of aligned cells with pairs of upper and lower cells separated by a common cathode electrode. The cathode electrodes are parallel strips corrugated in a series of rectangular waves, each flat elevated portion of a corrugation being embedded in an aperture of the insulator sheet and dividing the aperture into upper and lower cells interconnected by a tiny hole in the cathode. The parallel sides of a corrugation form walls of a cell. A single corrugated electrode thus forms a column of upper and lower cells across the panel. Pairs of associated anodes cross opposite ends of the apertures perpendicular to the common cathodes preferably in slots in the insulator to form rows of cells. Pairs of baseplates are sealed to the insulator sheet to form an hermetic unit.

United States Patent 72] Inventor George A. Kupsky Milford, NJ.

[21] Appl. No. 53,145

[22] Filed July 8, 1970 [45] Patented Nov. 9, 1971 [73] Assignee Burroughs Corporation Detroit, Mich.

[54] GAS CELL DISPLAY PANEL UTILIZING 1/1971 Bitzer etal Primary Examiner-John Kominski Att0rneys-Kenneth L. Miller and Charles S. Hall ABSTRACT: A display panel utilizing an array of gas-filled cells in an insulator sheet the cells being arranged in upper and lower layers of aligned cells with pairs of upper and lower cells separated by a common cathode electrode. The cathode electrodes are parallel strips corrugated in a series of rectangular waves, each flat elevated portion of a corrugation being embedded in an aperture of the insulator sheet and dividing the aperture into upper and lower cells interconnected by a tiny hole in the cathode. The parallel sides of a corrugation form walls of a cell. A single corrugated electrode thus forms a column of upper and lower cells across the panel. Pairs of associated anodes cross opposite ends of the apertures perpendicular to the common cathodes preferably in slots in the insulater to form rows of cells. Pairs of baseplates are sealed to the insulator sheet to form an hermetic unit.

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Ill/I l INVENTOR GEORGE A. KUPSKY GAS CELL DISPLAY PANEL UTILIZING CORRUGATED ELECTRODES BACKGROUND OF THE INVENTION Display panels comprising a plurality of gas-filled cells which can be turned on selectively to display a message are known in the art, but have thus far not become widely used commercial devices. In a recent development, a display panel has been invented having two layers of cells and utilizing cathodes in common between the layers. The cathodes are usually in the form of parallel metal strips, each having across its length a row of tiny apertures interconnecting pairs of gas cells in the upper and lower layers, thus forming an array of such apertures. The lower layer of cells is continuously scanned to maintain a cathode glow on the lower surface of the cathodes around the apertures. As information signals are applied to anodes of the upper layer of cells, synchronously with the scanning, the cathode glow spreads to the front surface of the cathode at the selected cell or cells to form a visible unit of a display.

For example, copending application, U.S. Ser. No. 855,448, of coownership herewith, discloses a display panel having columns of parallel flat cathode electrodes sandwiched between two plane layers of insulators, each cathode having a plurality of tiny apertures in a row across its length, the apertures in the electrodes being aligned to form a matrix. Each of the apertures interconnects upper and lower gas cells in the display panel. Pairs of front and rear anodes are aligned in slots along the ends of the paired cells and perpendicular to the cathodes. The gas-filled cells are sealed between plates to form a bilevel display panel of gas cells. However, the columns 'of cells crossed by the same anodes are physically interconnected for gas flow by the slots in which the anodes lie. During display the lower cells are continuously scanned to maintain cathode glow on the lower surface of the cathodes. When an information signal is received on an upper anode synchronously with the scanning of a lower cell the glow maintained in the lower cell spreads into the upper cell to form a visual display.

In the past such a display panel has required two layers of insulators, each having apertures therethrough to form upper and lower gas cells, with the apertured cathode sandwiched therebetween. This has proved to be expensive to produce because of the requirement for precision forming of the top and bottom insulator portions to prevent gas leakage, the number of steps required to construct the complete panel display system, and the necessity for accurately aligning the cathodes with respect to the cells.

It, therefore, is an object of this invention to provide a more simplified and economical gas cell display panel.

It is another object of this invention to provide a display panel utilizing a unitary insulator having a plurality of bilevel gas-filled cells.

It is still another object of this invention to provide a selfaligning cathode electrode structure in a gas cell display panel.

SUMMARY OF THE INVENTION Accordingly, the display panel of this invention includes a unitary insulator structure having a plurality of gas-filled cells therein. Cathode electrodes, each having a rectangular corrugated configuration, are positioned in parallel with their flat elevated portions embedded in apertures in the insulator thus dividing each aperture into upper and lower cells interconnected by a tiny hole in the cathode. The parallel sides of a corrugation form walls of a portion of a cell, the flat lower portions of the corrugations being flush against the body of the insulator. A single cathode thus forms a column of upper and lower cells across the panel in a unitary insulator sheet. Pairs of associated anodes cross opposite ends of the cells perpendicular to the common cathodes. preferably in slots in the in sulator, to form rows of display cells, and base plates are scaled to the insulator sheet to form an hermetic unit.

In the preferred embodiment the cathodes of the invention are individual strips. In a second embodiment of the invention the apertures in the insulating sheet may be formed to contain collars of insulating material, dividing the apertures into upper and lower portions connected by a central hole through the collar. The cathodes are formed by metallizing strips across the insulating sheets interconnecting the apertures of a column, the stripes being in substantially the shape of the corrugated strips of the preferred embodiment. In the second embodiment the upper and lower surfaces of the collar and the inner surfaces of the hole through the collar are metallized, the complete corrugated electrode being substantially the same in appearance as the preferred embodiment.

Other objects, advantages and features of this invention will become more fully apparent from the accompanying detailed description, appended claims, and drawings in which:

FIG. I is a perspective view of a gas cell display panel incorporating an embodiment of the cathode of the invention.

FIG. 2 shows a perspective view of the preferred embodiment of a cathode electrode fabricated under the principles of the invention.

FIG. 3 shows an enlarged cutaway view of a portion of a dis play panel incorporating the preferred embodiment of the invention.

FIG. 4 shows the view of FIG. 3 but incorporating a second embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. I, there is shown a portion of a gas cell display device having a unitary body block ll, formed of insulating material such as glass, ceramic or plastic. The insulating block or sheet 11 contains upper gas cells 13 and lower gas cells 15 separated by a common cathode 17. The block or sheet 11 is composed of insulating material such as glass, ceramic, mica or the like. The gas cells are arranged in an array of columns and rows with upper gas cells 13 and lower gas cells 15 aligned in pairs. The pairs of gas cells are interconnected by a tiny aperture 19, not more than 3 mils in diameter, in the common cathode 17. The cathodes are aligned in parallel with each cathode I7 defining a column of cells.

Upper and lower anodes 21, preferably in the form of wires, are aligned in parallel across the ends of the gas cells 13, I5 and perpendicular to cathodes 17, with pairs of anodes 21 defining rows of gas cells I3, 15, one pair of anodes being associated with a row of pairs of upper and lower gas cells. Preferably the anodes 21 are positioned in channels in the block- 11 to permit gaseous intercommunication between the gas cells interconnected by the anodes.

A constant voltage is maintained on the lower anodes 21 and the cathodes 17 are continuously scanned to maintain a low cathode glow on the lower surfaces of the cathodes 17 around the apertures 19. Information signals are fed to the upper anodes 21 synchronously with the scanning of the cathodes 17. Upon the concurrence of signals in an upper anode 21 and a cathode 17 the cathode glow in a lower gas cell 15 spreads into its paired upper gas cell I3 to form a unit of character or display in the display panel.

The gas cells l3, 15 are formed in apertures in the block 11. In the preferred embodiment the upper gas cells have a circular cross section, whereas the lower gas cells 15 have a rectangular cross section.

As shown in FIG. 2 the cathodes 17 of this invention are preferably metal strips having a series of square wave or rectangular corrugations 23 across their length. The corrugations 23 are inserted into the apertures of rectangular cross section with the flat elevated portion 25 of each corrugation forming the wall or partition between the upper and lower gas cells 13, 15. The small holes 19 are provided in the elevated portions 25 to form an interconnection between the upper and lower gas cells l3, 15. The parallel sides 27 of the corrugations 23 form walls of the lower gas cells I5 and the lower flat portions 29 of the corrugations 23 are flush against the lower surface of the block 11, as shown in the detail of FIG. 3.

The flat elevated portions 25 of the cathodes 17 thereby form the dividing partitions and common cathodes between the upper gas cells 13 and the lower gas cells 15. The cathodes l7 terminate at or slightly beyond the walls of the block 11 and have electrical terminals 31 for connections to cathode drivers (not shown).

The apertures of rectangular cross section in the block 11 for forming the lower gas cells 15 may have at least one dimension larger than the diameter of the upper portion of the apertures to form a shoulder 33 against which the elevated flat portions 25 of the corrugations 23 are seated.

The lower flat portions 29 of the corrugations together with the terminations 35 of the cathodes 17 may be seated in slots 37 in the block 11, so as to be flush with the surface of the block.

A transparent upper plate 39, as shown in FIG. 3, is sealed across the upper surface of the block 11 and a base plate 41 is sealed across the lower surface of the block to form the upper and lower boundaries of the gas cells l3, 15. The plates 39, 41 may be of glass, ceramic or similar insulative materials. The sides and ends of the panel may also be sealed, as by glass frits, to form an hermetic unit. 1

If preferred the upper and lower gas cells 13, 15 may both have. circular cross sections and the upwardly extending corrugations of the cathodes 17 may be in the form of right circular cylinders which are open on the sides.

The upper and lower gas cells 13, 15 may, of course, both have rectangular cross sections, if desired.

DETAILED DESCRIPTION OF A SECOND EMBODIMENT OF THE INVENTION In a second embodiment, the corrugated cathodes of the invention are formed directly on the insulating sheet 11. As shown in FIG. 4, the upper and lower cells l3, 15 are partially fonned in the sheet 11 by including within the apertures in the sheet a collar 43 of insulating material. The sheet 11 may be originally cast or extruded in this form as known in the art. Alternatively, the collar 43 may be formed separately and adhered to the walls of the apertures of block 11 by methods well known in the art.

Parallel stripes across the surface of the sheet 11 are then metallized to form column cathodes 45. The cathodes 45 are preferably the same width as the lower cells 15, and the metallized portions of the surfaces of the block 11 include a pair of opposing sides and the upper surface of the cell 15, i.e., the lower surface of the collar 43.

In order to maximize the rapid spread of glow from the cell 15 to the cell 13 upon concurrence of signals on the upper anode 21 and the cathode 45, the upper surface of the collar 43 and the inner surfaces of the hole 47 therethrough should also be metallized. As previously explained, the upper surface of the collar 43 forms a portion of the lower surface of the upper cell 13.

Suitable methods of metallizing the proper surfaces of the block 11 in the second embodiment are well known in the art.

For example, the surfaces not to be metallized may be covered, and the balance metallized by vapor deposition. Conversely all surfaces may be metallized, the areas to be permanently metallized then covered with protective material and the unwanted metal film etched away. The protective covering is then removed.

If desired the block 1 1 may be fabricated with shallow channels .in which the column electrodes of metal are striped across the block 11, as well known in the art of metal fabrication.

Iclaim:

l. A gas cell display panel comprising:

a unitary insulator having a plurality of rows of apertures therethrough,

a plurality of corrugated cathode electrodes arranged in parallel across said insulator and having flat elevated portions embedded in said apertures to em partitions In each aperture,

a plurality of anode electrodes arranged in parallel across the ends of said apertures perpendicular to said cathode electrodes, and

means for sealing said insulator to form an hermetic unit containing aligned pairs of gas cells.

2. The gas cell display panel of claim 1 wherein each of said flat elevated portions contains at least one tiny hole for gaseous intercommunication between said pairs of gas cells.

3. The gas cell display device of claim 2 wherein said apertures in said insulator have portions of circular cross section in one side of said insulator and portions of rectangular cross section in the other side of said insulator and wherein said flat elevated portions of said cathode electrodes are inserted into said rectangular portions.

4. The gas cell display device of claim 3 wherein said rectangular cross sections have at least one dimension greater than the diameter of said circular cross section forming shoulders against which edges of said flat elevated portions are seated.

5. The gas cell display panel of claim 2 including a collar of insulating material in each of said apertures extending from the walls thereof and wherein said corrugated cathode electrodes are formed by metallizing selected surfaces of said unitary insulator including the exposed surfaces of said collar.

6. The gas cell display panel of claim 2 wherein said anode electrodes are positioned in channels in said insulator block said channels also providing gaseous intercommunication between said apertures in said insulator crossed by said anode electrodes.

7. An electrode for use in a gas cell display device having two layers of aligned gas cells in apertures in a single insulator comprising a strip of metal formed in a series of spaced corrugations, each of said corrugations being of rectangular configuration for inserting into said apertures in said insulator for acting as both a structural partition and a common electrode between aligned gas cells.

8. The electrode of claim 7 wherein said corrugations contain small holes for gaseous intercommunication between the aligned gas cells when said corrugations are inserted into the apertures of said'insulator.

* l i i 

1. A gas cell display panel comprising: a unitary insulator having a plurality of rows of apertures therethrough, a plurality of corrugated cathode electrodes arranged in parallel across said insulator and having flat elevated portions embedded in said apertures to form partitions in each aperture, a plurality of anode electrodes arranged in parallel across the ends of said apertures perpendicular to said cathode electrodes, and means for sealing said insulator to form an hermetic unit containing aligned pairs of gas cells.
 2. The gas cell display panel of claim 1 wherein each of said flat elevated portions contains at least one tiny hole for gaseous intercommunication between said pairs of gas cells.
 3. The gas cell display device of claim 2 wherein said apertures in said insulator have portions of circular cross section in one side of said insulator and portions of rectangular cross section in the other side of said insulator and wherein said flat elevated portions of said cathode electrodes are inserted into said rectangular portions.
 4. The gas cell display device of claim 3 wherein said rectangular cross sections have at least one dimension greater than the diameter of said circular cross section forming shoulders against which edges of said flat elevated portions are seated.
 5. The gas cell display panel of claim 2 including a collar of insulating material in each of said apertures extending from the walls thereof and wherein said corrugated cathode electrodes are formed by metallizing selected surfaces of said unitary insulator including the exposed surfaces of said collar.
 6. The gas cell display panel of claim 2 wherein said anode electrodes are positioned in channels in said insulator block said channels also providing gaseous intercommunication between said apertures in said insulator crossed by said anode electrodes.
 7. An electrode for use in a gas cell display device having two layers of aligned gas cells in apertures in a single insulator comprising a strip of metal formed in a series of spaced corrugations, each of said corrugations being of rectangular configuration for inserting into said apertures in said insulator for acting as both a structural partition and a common electrode between aligned gas cells.
 8. The electrode of claim 7 wherein said corrugations contain small holes for gaseous intercommunication between the aligned gas cells when said corrugations are inserted into the apertures of said insulator. 